K2[(UO2)As2O7] – the First Uranium Polyarsenate |
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| Authors: | Evgeny V. Alekseev Sergey V. Krivovichev Prof. Dr. Wulf Depmeier |
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| Affiliation: | 1. Kiel/Deutschland, Universit?t Kiel, Institut für Geowissenschaften;2. Nizhny Novgorod / Russia, Nizhny Novgorod State University;3. Department of Crystallography, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg/Russia, Fax: (+,) 812 3284418Department of Crystallography, St. Petersburg State University, University Emb. 7/9, 199034 St. Petersburg/Russia, Fax: (+,) 812 3284418 |
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| Abstract: | Yellowish crystals of K2[(UO2)As2O7] ( 1 ) have been synthesized by solid‐state reactions method. The structure of 1 [orthorhombic, Pmmn, a = 12.601(2), b = 13.242(2), c = 5.621(1) Å, V = 937.9(3) Å3, Z = 4] has been solved by direct methods and refined to R1 = 0.049, wR2 = 0.1060 for 1059 observed reflections. The structure of 1 is based upon [(UO2)As2O7]2? sheets formed by corner sharing between [UO6]6? distorted octahedra and [As2O7]4? polyarsenate groups. The K+ cations are either in eightfold or tenfold coordination and are located between the sheets. The topology of the uranyl arsenate sheet is related to silicate minerals of the melilite group and related synthetic silicate, aluminate and germanate compounds. |
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| Keywords: | Uranium Polyarsenate Crystal structure |
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